We investigated how eicosapentaenoic acid (EPA), part of the omega-3 fatty acids family, influences breast cancer stem cells (BCSC). Using specialized in vitro models derived from mammosphere cultures, we observed that BCSCs exhibited a unique fatty acid metabolism, especially in lipogenesis, which is the process of creating fats.
One of the key enzymes, stearoyl-CoA desaturase 1 (SCD1), was especially active in these cells, promoting their growth and ability to self-renew. When we inhibited SCD1, whether through specific drugs or small interfering RNA (siRNA) techniques, we noticed a significant reduction in both growth and self-renewal of the BCSCs. This indicates SCD1 plays an essential role in their survival.
Moreover, we discovered elevated SCD1 and related lipogenic enzymes in human breast cancer tissues, pointing to their correlation with tumor grade. Notably, when we treated BCSCs with EPA, we found a decrease in the expression of lipogenic enzymes, leading to reduced self-renewal and growth of these cancer stem cells. In animal models, dietary EPA also resulted in a significant reduction of tumor load, showcasing its potential as a therapeutic avenue.
Overall, our findings highlight the critical role of increased lipogenesis in the growth and maintenance of BCSCs, and they suggest that EPA could be a valuable player in targeting this process to combat breast cancer.